Collapsible tube closure structure



D. C. MADDUX COLLAPSIBLE TUBE CLOSURE STRUCTURE Aug. 16, 1955 2 Sheets-Sheet 1 Filed June 23, 1954 INVENTOR Juana fi Mark/ax BY M M RNEY Aug. 16, 1955 D. c. MADDUX COLLAPSIBLE TUBE CLOSURE STRUCTURE 2 Sheets-Sheet 2 Filed June 23, 1954 United States Patent COLLAPSIBLE TUBE CLOSURE STRUCTURE Duane C. Maddux, Burbank, Caiif.

Application June 23, 1954, Serial No. 438,303

Claims. (Cl. 222-92) This invention relates to closure means for collapsible, thin-walled tubular containers and particularly to collapsible tube closures which open under increase of pressure applied to the material in the tube and which auto matically close upon decrease in said pressure.

This is a continuation in part of my pending application Ser. No. 363,136, filed June 22, 1953, now abandoned, and is an improvement over the invention of my prior Patent Number 2,130,284, dated September 13, 1938.

An object of the invention is to provide a secure closure at the tube end formed by the adjacent thin end walls of the tube yieldingly pressed together fiatwise over a predetermined area at the end edges.

Another object of the invention is to apply the yielding closing pressure over the outer surfaces of the tube end walls at said predetermined area adjacent to said end edges. In this way these portions of the tube walls form a flat, nozzle-like slit with the inner surfaces of the tube walls pressed together over a considerable area extending back from the tube edges. This provides a smoothly con tracting symmetrical guidance of the orifice flow to project the discharge directly outward and away from the orifice edges and secures a tight sealing of the closure under the lower pressures on the material in the tube while preserving at all times a dependable opening response to increased pressures thereon.

Further objects of the invention particularly in the free floating of the pressure applying members at the outer surfaces of the nozzle slit and the special formation of the entire end closure means as a single integral clip of sheet metal for ready application to the tube end will appear from the following specification taken in connection with the accompanying drawings, in which Fig. 1 is a side elevation of a collapsible tube having the closure means of the present invention applied thereto,

Fig. 2 is a bottom plan view of Fig. 1,

Fig. 3 is a fragmentary, enlarged, elevational view of the right hand side of Fig. 2,

Figs. 4 and 5 are enlarged, fragmentary sectional views taken on the lines 44 and 55, respectively, of Fig. 1,

Fig. 6 is a side elevation showing some of the steps in the manufacture of the closure means element prior to the final folding thereof to prepare it for application to a container,

Fig. 7 is an enlarged side elevation of the closure element as delivered from the series of manufacturing operations shown in Fig. 6,

Fig. 8 is a transverse, sectional view taken on the line 88 of Fig. 7,

Fig. 9 is a side elevation of the finished closure means ready for application to a container,

Fig. 10 is an enlarged, transverse, sectional view taken on the line 1010 of Fig. 9,

Fig. 11 is a side elevation of a container prepared for reception and application of the closure means,

Fig. 12 is an end elevation of the container shown in Fig. 11 with the closure means applied thereto and before the closure means is secured thereto,

Fig. 13 is an enlarged diagrammatic longitudinal sectional view illustrating the action of the orifice in delivering the material under pressure applied to it and sealing against leakage as the pressure is released,

Fig. 14 is an end view on enlarged scale of a modified closure means applied to a collapsible tube,

Fig. 15 is a plan view of the tube and closure shown in Fig. 14,

Fig. 16 is a side view of the same,

Fig. 17 is a cross-sectional View taken on line 17-17 of Fig. 15 looking in the direction of the arrows,

Fig. 18 is a partial longitudinal sectional view taken on the line 1818 of Fig. 15 looking in the direction Z the closure as the tube end enters between the jaws.

The closure means 1 is formed from a single piece of resilient sheet metal of generally rectangular outline in plan and folded on itself along its medial longitudinal line L to an approximate V-shape as best shown in Figs. 8, 9 and 10 before fastening on a container. The center portions of the blank are cut away incident to formation of the narrow side bars 2, 2 which are offset (see Fig. 8) from the plane of the blank; each of said side bars having at the mid length thereof a stem portion 3 terminating in a transversely extending jaw portion 4 parallel to and slightly spaced from the central longi tudinal fold line L.

The closure means is adapted for production by a punch press equipped with a progressive die formation in which the various operations are performed in sequence and Fig. 6 shows a portion of the strip as it passes through the die just prior to the final folding operation. The stem portions 3, 3 lie mainly in the plane of the side bars 2, 2 and adjacent their distal ends are bent toward the plane of the rest of the blank as at 5, 5 and the jaw portions 4, 4 are bent as at 6, 6 to bring the terminal edges 13, 13 and surfaces 7, 7 parallel to but at the opposite sides of the plane of the blank. When in the final forming operation the blank is folded on itself to the extent shown in Fig. 10, the offsetting of the jaw elements causes the jaw surfaces 7, 7 to engage each other in a resilient interengagement effecting a spring bias in each jaw toward the other and since they are of the same size and formed from the same metal, the bias of each will balance the other. Incident to the other forming operations, the ends of the blank are provided with oppositely disposed embossed lug portions 8, 8 and cooperating holes 9, 9 which serve to crimp the container walls between them to secure the closure means to the container as best shown in Fig. 5.

The container here shown by way of example comprises a soft metal tube 10 extruded from a blank with the unextruded portion of the blank forming a closed end 11. The tube is filled with the desired contentsto the desired extent and the end is flattened as shown in Fig. 11.

5 that at such time the tube would be inverted from the cation of the closure means to the tube, it is to be noted in Figs. 9 and 10 that the outer or distal ends of the jaw elements 4, 4 are slightly below the fold in the end por tions and in Fig. 10 it is to be noted that the opposed faces 7, 7 of the jaws are convergingly inclined toward the outer end of the fold and that the bends 6, 6 in the jaws effect smooth converging surfaces facilitating entry of the container end, walls therebetween. Referring to the construction shown in my said prior patent, experience showed'that it was not adapted for use with automatic machinesfor filling and closing containers of the character for which the closure means was adapted.

In the closure means of the. present invention, the flattened tube end walls engage the curved and converging side faces of the jaws and readily enter: therebetween and incident to the completion of the closure, the said side surfaces of the jaws will'be brought into parallelism with each other and with the tube end walls as best shown in Fig.4; the entry of the tube between the jaws and the completion of the folding of the closure means incident to applying it to the tube serving to increase the pressure exerted by the jaws on the tube walls. The oflsetting of the side bars 2, 2 serves. to allow the tube contents to flow freely toward the closure means and the sloping edges 12 extending from the side bars to points adjacent the ends of the jaws serve to direct the tube contents toward the closure so that all of the tube contents may be readily expelled.

The action of the above closure means is believed to be obvious from this description. Upon application of etxernal pressure on the tube the contents will be forced through the end of the tube held normally closed by the jaws 4, 4 and upon cessation of such pressure, the jaws will seal the opening.

This closure means-is designed for manufacture and application by automatic machines which operate at ratespwhich may be of the order of forty or more tubes per minute and accordingly, the closure means so applied must be so designed as to completely eliminate the possibility of imperfect application to the tubes. The novel and improved shaping of the jaws and the stem portions thereof achieves this result with the soft and fragile tubes now in common use and may even be found acceptable for tubes formed from other materials which are even softer than the metals now in use, such for instance as the organic plastics.

In the final application of the closure means, to the flattened end .of the tube 10 as illustrated in central section in Fig. 13, the tube edge is engaged against the inner surface of bend 15, the free center portion of the tube end thus protruding a small distance 16 beyond the edges of the terminal edges 13, 13 of the jaw portions 4;

These jaws 4 are pressed against theside surfaces of the tube by forces dependent on two factors. The first factor (Figs. 8 and 10) is the positioning of the jaws in the flat blank, the formation being such as to bring them a small distance 17 beyond the surface 18 of the blank. This distance 17 is, in the example shown, suflicient to bring the terminal edges 13 together with a spring bias in the partially bent form of the closure shown in Fig. 10. Further flattening of the closure blank will accentuate the'spring pressure between these jaws but in advance of this final flattening the end 14 of the tube inserted between the jaws (Fig. 12) has separated them and correspondingly increased the pressure between them, this being the second factor above noted.

' With the closure means finally in place (Figs. 1 to 4) the tube end is clamped and permanently closed at each side leaving the center portion gripped between the inner substantially flat surfaces 7, 7 of the jaws 4. It is of critical importance to concentrate this pressure to force the inner end surfaces 19 of the tube together at this area of contact of the tube with the surfaces 7 (Fig. 13). The film F formed by this pressure in this area is thin in proportion to its axial extent and acts as an effective seal during the idle periods of the tube. A tube filled with a liquid such as water has effectively held its contents from leakage and the evaporation from the edge of the film is reduced to a minimum. With many composite materials evaporation from the outer portions of the film compacts it there under the applied pressure and blocks escape of volatiles from the material within the tube. The

sealing action is progressively increased with inward' growth of the evaporated area backward from the end edge and soon reaches the point of stoppage within the pressed The depth of the usual film F is 0.01" to 0.10" or more and its thickness 0.001" to 0.0001" 'or less in actual practice, so that the film thickness is not over one-tenth of the film depth and may be less.

At its inner portion the film merges into the wedge formation of the material in the tube between the curved surfaces 23, 23 corresponding to the bends 6, the outer surfaces of the tube tending to follow these surfaces particularly where pressure has been applied to the tube; and, as shown, this pressure may carry the tube Walls into contact also with the bends 5 and even the stem portions 3 (Figs. 3 and 4).

With this formation of the closure means a relatively large total force is available to spread jaws 4 for extrusion of the contained material through the center' portion of the tube end the walls of which are separated by the pressure applied to the material to overcome the pressure applied by the jaws. As the opening pressure is applied by the fingers of the user squeezing the tube the contained material distributes this pressure to the inner surfaces of the tube and progressively increases it over a wide area much greater than that of the film F. Consequently the total force applied outward to the opening of the jaws. 4 is much larger than the total compressing force applied by the jaws 4 to the film F even though the intensity of the pressure of the jaws on the film area may greatly exceed the intensity of the opening pressure applied by the material.

The surfaces 19, 19 are thus opened by relatively moderate internal pressure of the material and in opening they tend to reduce the internal pressure by the escape of the material between these surfaces. is maintained by the user compressing the tube and a thin ribbon is rapidly extruded the full width of surfaces 19.

The ejector action will tend to be in a continuous series 7 of surges which may with some materials be evidenced by a cross-ribbed appearance of the ribbon.

The extruded ribbon is usually very thin because the reduction in pressure occurring with the release of the matenal tends to limit the opening of the jaws, and also because the central portion of the tube end has at each side a rigid anchorage with practically no transverse yielding and any continued spreading of the tube walls at surfaces 19 involves transverse stretching of these walls and corresponding increased resistance to further expansion.

,The material extrudes at high velocity clearing the passage between surfaces 19 and on cessation of the opening pressure these surfaces are again pressed together to reform the sealing film F between them.

In the modification illustrated in Figs. 14 to 21 the tube 40 is closed at the end (not shown) in any desired manner,

for instance, by a folded strip gripping the flattened edges and the discharge end is provided with the closure means 31 having the arched side bars 32 and stem portions 33 carrying the jaw portions 34. The stem portions (Figs. 20 and 2]) 33 are inclined toward each other outward fromthe side bars'32, and then bend inward at 35 to the jaws 34, which in turn have the bends 36 bringing the inner:

Adequate pressure 44 may be provided with short slits 50 spaced to be located at the ends of jaws 34 and just within the edges 51 of the closure means and reaching backward to terminate at the bends 36 of the jaws 34. Lugs 38 and cooperating holes 39 are provided to interlock the sides of the closure means on the flat end portions of the tube 40 with the sloping edges 42 leading to the central jaw gripped area between slits 50. The ends 43 of jaws 34 are slightly back a distance 46 from the tube end 44 and the jaw pressure is exerted substantially uniformly over the said gripped area to press the inner surfaces 49 of the tube together on the film F of the material between them.

This gripped area of surfaces 49 with the thin film F between them automatically seals the tube discharge upon cessation of the pressure on the tube and this guardian jaw pressure will be made sufficient to reduce the film thickness to be only a fraction of the depth of the film from the end edge 44 of the tube, but the gripping pressure will be limited by the formation and bending of the parts to be overcome by the outward pressure of the tube walls against the jaws or against the jaws and stems 33 to slightly open the jaws and separate the surfaces 49 for discharge of the material (Fig. 19) in a ribbon of desired volume. Preferably the thickness of the ribbon discharge will be such as to provide convenient control of the amount under the pressure applied. Normally a sustained pressure on the tube will maintain a continuous outflow, but the tendency of the jaw opening and resultant flow at considerable velocity between surfaces 49 will be to sharply reduce the outward pressure so that surges will result as the pressure alternately builds up and reduces in rapid succession. The discharge of material is substantially uniform for a given pressure delivering a flat thin ribbon of the contained material at high velocity so that the depth of accumulation of the ribbon on a surface, brush or the like will be accurately determined by the user either holding the tube end at a definite point or, as is more usual, moving it backward opposite to the direction of outflow. The rate of this backward movement is readily gauged to give the desired distribution of the discharge from a thick heavy deposit by a slow retraction to a drawn-out, film-like strip by a swift backward movement.

Then as the pressure is released to shut off the outflow slight additional movement of the tube end will wipe and clean the edges as the jaws press the orifice surfaces tightly on the film F to complete the closure. The material is thus re-sealed securely against leakage and kept ready at any time for intentional release by definitely applied and maintained pressure on the material in the tube.

The closure means is widely adaptable to a variety of materials, liquids, creams, greases, glues, cements and the like. The closure is fabricated from strip material by a series of die cutting and shaping operations and is readily applied to seal the flattened end of the empty tube so that the tube may be subsequently filled and the final seal applied at the opposite end.

The tube itself may be of any soft, thin metal or other material suitable for collapsible tubing of the desired size, and the closure clip will preferably be of spring metal of a guage determined by the size of the tube and the sealing pressures desired. In the drawings the thickness of the tube walls and closure clip metal are exaggerated somewhat. The Walls 10, 40 are typically like those of the usual collapsible tubing and the clip 1, 31 is of tin plated steel about .015" in thickness for a tube end 1%" wide.

The principle of the invention is not confined to the embodiments shown and the closure clip may be modified as desired in shape to correspondingly adapt the form of the end surfaces to the particular material being dispensed. For instance, the edge 45 may be rounded at each corner to present an arcuate terminal portion with the delivery opening at the apex and this opening may be narrowed to any desired width for the discharge. In-

stead of a single central stem 3, 33 for each jaw 4, 34 spaced stems may be provided one at each side to minimize any tendency of the jaws to open unevenlymore on one side than the other.

The depth of the jaw surfaces 7, 37 may be varied with the extent of the seal desired with the various materials being dispensed, greater depth being indicated where lighter volatiles are to be retained by the sealing film F; but the higher intensities of pressures on the limited areas of lesser depths will similarly tend to provide an effective seal by thinning of this film F between the surfaces 19, 49.

Other adaptations and variations may be adopted within the essence of the disclosure without departing from the principle of the invention as set forth in the appended claims.

I claim:

1. The combination with a flexible walled container for a soft extrudible material and having an opening between end walls thereof, of a closure means therefor comprising a structure having portions clamped on the container end walls at said opening and carrying a pair of opposite jaws having inner surfaces which are flat and parallel and in contact with each side of the container over a predetermined area located immediately adjacent the end edge of said opening, means resiliently supporting said jaws from said structure to press the inner surfaces of the gripped container walls evenly together over said entire predetermined area in advance of said opening with a thin film of material intervening between them throughout said area and forming the seal for the material within the tube, said jaws being out of contact with the adjacent clamped portions of said structure and yieldingly separating on a predetermined increase in pressure on the material in the tube to permit expansion of said opening and extrusion of material therethrough under said pressure and automatically reclosing said opening and reforming said sealing film between said jaw pressed surfaces in said predetermined area upon cessation of said opening pressure.

2. The combination of a flexible walled container and a closure means therefor as set forth in claim 1 in which the inner jaw surfaces are curved outward in advance of said substantially parallel surfaces permitting outward expansion of the container walls into contact with said curved surfaces to augment the outward opening pressure of said jaws.

3. The combination of a flexible walled container and a closure means therefor as set forth in claim 1 in which the container end at each side of said opening has a slit at opposite ends of the corresponding jaw and extending for a predetermined distance inward from the container end.

4. The combination of a flexible walled container and a closure means therefor as set forth in claim 1 in which the container end at each side of said opening has a slit at opposite ends of the corresponding jaw and extending for a predetermined distance inward from the container end in the free space between the jaw end and the clamped structure.

5. The combination of a flexible walled container and a closure means therefor as set forth in claim 1 in which the container end at each side of said opening has a slit at opposite ends of the corresponding jaw and extending for a predetermined distance inward from the container end in the free space between the jaw end and the clamped structure, said slits having closely spaced edges remaining substantially in contact in the open position of said jaws.

References Cited in the file of this patent UNITED STATES PATENTS 1,690,654 Trotter Nov. 6, 1928 1,945,612 Lacher Feb. 6, 1934 2,130,284 Maddux Sept. 13, 1938 2,665,033 Robertson Ian. 5, 1954 

